The probability of selecting a rotten apple randomly from a heap of 900 apples is 0.18. What is the number of rotten apples in the heap?
A bag contains 15 white and some black balls. If the probability of drawing a black ball from the bag is thrice that of drawing a white ball, find the number of black balls in the bag.
Let the number of black balls in the bag be x.
Number of white balls = 15
Hence, total number of balls in the bag = x + 15
Given, P(black ball) = 3 x P(white ball)
Thus, the number of black balls in the bag is 45.
Two different dice are thrown together. Find the probability that the numbers obtained have
(i) even sum, and
(ii) even product
A number is selected at random from first 50 natural numbers. Find the probability that it is a multiple of 3 and 4.
A card is drawn from a well shuffled deck of 52 cards. Find the probability of getting
(i) a king of red colour
(ii) a face card
(iii) the queen of diamonds.